package com.leyou.common.utils;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.List;
import java.util.Map;

/**
 * @author: HuYi.Zhang
 * @create: 2018-04-24 17:20
 **/
public class JsonUtils {


    public static final ObjectMapper mapper = new ObjectMapper();

    private static final Logger logger = LoggerFactory.getLogger(JsonUtils.class);

    public static String toString(Object obj) {
        if (obj == null) {
            return null;
        }
        if (obj.getClass() == String.class) {
            return (String) obj;
        }
        try {
            return mapper.writeValueAsString(obj);
        } catch (JsonProcessingException e) {
            logger.error("json序列化出错：" + obj, e);
            return null;
        }
    }

    public static <T> T toBean(String json, Class<T> tClass) {
        try {
            return mapper.readValue(json, tClass);
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }

    public static <E> List<E> toList(String json, Class<E> eClass) {
        try {
            return mapper.readValue(json, mapper.getTypeFactory().constructCollectionType(List.class, eClass));
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }


    public static <K, V> Map<K, V> toMap(String json, Class<K> kClass, Class<V> vClass) {
        try {
            return mapper.readValue(json, mapper.getTypeFactory().constructMapType(Map.class, kClass, vClass));
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }


    public static <T> T nativeRead(String json, TypeReference<T> type) {
        try {
            return mapper.readValue(json, type);
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }

    /*
     * json做两件事序列化和反序列化
     * toString是序列化：对象变成字符串
     *toBean,toMap,toList都是反序列化：字符串变成对象
     * */
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    static class User {
        String name;
        Integer age;

    }

    /*public static void main(String[] args) {
        User user = new User("jack", 21);
        //toString
      *//*  String json = toString(user);
        System.out.println("json=" + json);*//*
        //反序列化
        //User user1 = toBean(json, User.class);
        //System.out.println("user1 = "+ user1);
        //toList
    *//*    json="[20,-10,5,15]";
        List<Integer> list = toList(json, Integer.class);
        System.out.println("list ="+list);*//*

        //toMap
    *//*  String json = "{\"name\":\"jack\",\"age\":\"21\"}";
        Map<String, String> map = toMap(json, String.class, String.class);
        System.out.println("map = "+ map);*//*
    //naticeRead
    String json = "[{\"name\":\"jack\",\"age\":\"21\"},{\"name\":\"Rouse\",\"age\":\"18\"}]";
        List<Map<String, String>> maps = nativeRead(json, new TypeReference<List<Map<String, String>>>() {

        });
        for (Map<String, String> map : maps) {
            System.out.println("map = " + map);

        }
    }
*/

}

//        版权声明：本文为CSDN博主「zcylxzyh」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
//        原文链接：https://blog.csdn.net/zcylxzyh/article/details/97616746
